Buzzing pyrotechnic device and method

ABSTRACT

A pyrotechnic device and method for producing same which produces a novel buzzing sound effect, the device comprising a closed reaction chamber filled with a pyrotechnic whistling composition, the reaction chamber being vented or choked to produce the buzzing sound effect.

nited States Patent [191 Klecak BUZZING PYROTECHNIC DEVICE AND METHOD [451 Feb. 26, 1974 3,678,855 7/1972 Semel 102/31 OTHER PUBLICATIONS Pyrotechnics, by Geo. W. Weingart; Chem. Pub. Co., N.Y.; 2nd Edition, 1947; pp. 180-181.

The Triumph Fusee & Fireworks Co., Elkton, Md, (Catalog), 1934, p. 7 required.

Primary Examiner-Robert F. Stahl Attorney, Agent, or Firm-11. Ross Workman [57] ABSTRACT A pyrotechnic device and method for producing same which produces a novel buzzing sound effect, the device comprising a closed reaction chamber filled with a pyrotechnic whistling composition, the reaction chamber being vented or choked to produce the buzzing sound effect.

5 Claims, 3 Drawing Figures BACKGROUND 1. Field of the Invention The invention relates to pyrotechnical devices and methods and more particularly to an improved device and method for producing a novel buzzing sound effect.

2. The Prior Art Pyrotechnics is the art and science of creating and utilizing the heat effects and products from exothermically reacting, predominantly solid mixtures or compounds when the reaction is generally non-explosive and relatively slow, self-sustaining and self-contained. Pyrotechnics is one of three closely related technologies, the other two including explosives and propellants. Pyrotechnics is essentially concerned with solid ingredients while explosives and propellants may be solids or liquids.

A pyrotechnic process differs from ordinary combustion by not requiring the presence of ambient air, at least not in a predominant way. Once the pyrotechnic process is triggered by a small external force, it may take its course in complete isolation from external parts or delicate components and perform equally well on land, in water, or in air. Most commonly, pyrotechnics are used to provide light and sound effects.

Pyrotechnic sound effects are well-known and are one of the principal values of pyrotechnic devices. Conventionally, salutes and maroons have provided the loud explosive sounds at fireworks displays. More recently, pyrotechnic whistles have been introduced and have proven to be very popular. Historically, many attempts have been made to develop new desirable sounds for pyrotechnic devices. Several attempts have been made to develop a buzzing pyrotechnic device. The best known attempt comprises a tube having a wing or flange secured to one end. The tube is filled with a propellant composition which, when ignited, induces a spiral and vertically ascending motion to the tube. A hissing sound results when the wing or flange and spiraling casing are moved against the resistance of air and the sound therefrom is coupled with the sound of the escaping gas. For example, see U. S. Pat. Nos. 2,443,298 and 2,443,299.

Until this present invention, however, no pyrotechnic device has been known which emits a buzzing sound as a result of pyrotechnic reaction.

BRIEF DESCRIPTION AND OBJECTS OF THE INVENTION The present invention is a pyrotechnic device and method producing a novel buzzing sound effect resulting from choking or venting a reaction chamber containing a pyrotechnic whistling composition. The buzzing device can have application in various pyrotechnical effects such as rockets, wheel drivers, aerial shells-both in break and trajectoryspiral ascending aerial devices, and other moving and stationary effects.

It is, therefore, a primary object of the present invention to provide a novel pyrotechnic device which develops a buzzing sound effect.

It is another primary object of the present invention to provide an improved method for preparing a buzzing pyrotechnic device.

These and other objects and features of the present invention will become more fully apparent from the following description and appended claims taken in conjunction with the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a fragmentary cross-sectional view of a presently preferred embodiment of the invention;

FIG. 2 is a schematic perspective view of another preferred way of forming a pyrotechnic device according to the present invention; and

FIG. 3 is still another presently preferred pyrotechnic device with a vent in the curved periphery thereof.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention contemplates the use of a conventional pyrotechnic whistling composition which is placed in a reaction chamber. As will be hereinafter more fully described, the reaction chamber is choked or vented to stifle or repress the whistling sound which would normally result from the composition.

In this specification, a pyrotechnic whistling mixture is defined as any pyrotechnical mixture containing an oxidizer and a fuel in such proportions as to create a pyrotechnic whistling sound effect. While any pyrotechnic whistle mixture can be used in the illustrated embodiment of the invention, considerations of cost, safety and availability suggest that preferred whistling mixtures include potassium perchlorate with sodium salicylate, or with sodium benzoate, or with potassium benzoate.

In this specification, the term choked reaction chamber is defined as any enclosed chamber sufficiently strong to keep from rupturing from the gas pressure produced by the whistling mixture combustion and having one or more openings each of which has a diameter which is smaller than the inside diameter of the reaction chamber. Also, in this specification, the terms choke, vent and constriction may be used interchangeably.

THE STRUCTURE AND COMPOSITION Referring now to the drawings, a cylindrical reaction chamber generally designated 12 comprises a parallel wound paper tube 14 with a clay plug 16 secured in one end thereof. The reaction chamber has been filled with a pyrotechnic whistling mixture 18.

A second clay plug 20 is secured in the tube 14 opposite the plug 16, the plug 20 having an annular bore 22 essentially central thereof. The bore 22 comprises a vent or choke for the reaction chamber 12. The preferred size of the vent openings depends upon the diameter of the reaction chamber. The lower size limit seems to depend upon the ease of ignition and burning preservation of the whistling mixture. If the vent opening or openings are less than I/ 1 6th of an inch in diameter, regardless of the reaction chamber size, the composition is ignited only with great difficulty and burning of the whistling mixture is not easily sustained. The upper size limit of the vents approaches approximately one-half of the inside diameter of the reaction chamber. If the vent openings are greater than one-half the diameter of the reaction chamber, the buzzing sound appears to be superseded by hissing and/or whistling of the composition. Also, a great portion of the propelling force of the device is lost.

The most effective size of the vent 22 appears to be approximately one-third of the inside diameter of the 7 reaction chamber. This size gives a loud buzzing sound and minimizes hissing or whistling. Also, a strong propelling force results.

The vent or choke can be made in any one of a variety of convenient ways. When the plug is in place, a drill or other boring means can be used to form the vent 22. Alternatively, a die can be used to form the bore 22 at such time as the plug 20 is solidified in the casing 14. Also, if desired, the technique illustrated in FIG. 2 can be used. In FIG. 2, a cylindrical reaction chamber 30 is formed by overlaying wet strips of paper and paste. When the chamber has been formed, it will still be relatively pliable and a cord 32 can be used to constrict the lower end 34 of the casing 30 thereby forming the choke. When the casing dries, it will solidify and the choke will be permanent.

Also, as shown in FIG. 3, a cylindrical reaction chamber 40 can be provided with a vent 42 at a desired location along its curved length. While only a single vent is shown in each of the reaction chambers in FIGS. 1-3, a plurality of vents could be successfully used. It has been found, for example, that another vent (not shown) opposite the vent 42 in the reaction chamber 40 (see FIG. 3) results in a highly satisfactory buzzing sound effect.

In the illustrated embodiment, the reaction chamber is shown as tubular which has been found to accommodate ease in loading the whistling mixture and which is easily available. Clearly, however, any suitable reaction chamber, including a spherical reaction chamber, could be used. Also, the reaction chamber can be of any convenient size. Larger reaction chambers have been found to develop louder buzzing sound. By way of example, the reaction chamber illustrated in FIG. 1 has an inside diameter of one-half of an inch.

While the precise mechanism producing the buzzing sound in the reaction chamber is not known, it is currently believed that the decomposition of aromatic acids or their salts through the oxidation process progresses in an oscillating manner whereby the crystals react in a rhythmic fashion. The reaction rhythmically accelerates and stops at generally uniform, closely spaced intervals which leads to alternation of high pressure and rarefaction in the reaction chamber. This pressure oscillation, upon reaching the chokes or vents, produces a loud crackling in the open air. When these pressure oscillations are multiplied in frequency as the pyrotechnic composition burns, a loud buzzing sound is produced.

THE METHOD According to the presently preferred method embodiment of the invention, a reaction chamber is obtained and filled with a pyrotechnic whistling mixture. Thereafter, the chamber is provided with one or more chokes or vents which may range in diameter from l/16th of an inch to approximately one-half the inside diameter of the reaction chamber.

Where a cylindrical tube is used for forming the reaction chamber, one end of the tube may first be provided with powdered clay which is tightly compressed in the tube into a wafer or disk sealing one end. Thereafter, the whistling mixture is placed in the tube leaving at least sufficient space at the opposite open end of the tube to accommodate an additional clay disk. One or both of the disks may then be drilled to provide a choke or vent.

Alternatively, the powdered clay, when poured into the tube for forming into a disk, may be situated around a die such that the choke or vent is automatically formed when the clay is compressed.

As previously described, vents may be placed at any desired location in the reaction chamber and more than one vent can be used.

The invention herein disclosed can be more fully understood by the following examples:

EXAMPLE 1 A pyrotechnic whistling mixture was produced by weighing 72.5 grains finely powdered potassium perchlorate and mixing the potassium perchlorate thoroughly with 27.5 grains of finely powdered sodium salicylate.

A parallel wound Kraft paper tube having an inside diameter of inch and a length of 2 inches was obtained. The tube was held upright on a firm surface and about 10 grains of powdered clay was rammed in with blows from a mallet to form a hard plug in one end of the tube. The whistling mixture was then rammed in on top of the clay plug and then the other end of the tube was also plugged with clay as before. A hole, Vs inch in diameter, was drilled through the first clay plug just to the whistling mixture and a piece of /s inch diameter fireworks fuse, otherwise known as Bickford fuse, was placed through the hole to contact the mixture.

Upon ignition, it was found that the device developed a very loud buzzing and shot around on the ground and into the air in a very rapid and aimless manner.

EXAMPLE 2 A pyrotechnic whistling mixture was prepared and rammed in a tube by practicing the steps of Example 1. Instead of drilling the vent through the clay, however, it was drilled through the side of the tube. Upon ignition, the device performed in the same manner as in Example 1.

EXAMPLE 3 A pyrotechnic whistling mixture was prepared by weighing 30 grains finely powdered potassium chlorate and mixing the potassium chlorate with 10 grains gallic acid. The mixture was rammed in a tube and vent drilled as in Example 1. Upon ignition, the device performed in the same manner as in Example 1.

EXAMPLE 4 A pyrotechnic whistling mixture was prepared by weighing 30 grains finely powdered potassium benzoate and mixing the potassium benzoate with grains potassium perchlorate. The mixture was rammed in a tube and vent drilled as in Example 1. Upon ignition, the device performed in the same manner as in Example 1.

EXAMPLE 5 A pyrotechnic whistling mixture was prepared and rammed in a tube by practicing the steps in Example 2. However, instead of drilling only one vent hole through the side of the tube, two holes were drilled, one near each end of the tube and on opposite sides so that when the device was ignited it would have a spinning motion. Upon ignition, the device developed a very loud buzzing sound and spun around on the ground and into the air in a very rapid and aimless manner.

EX'XMPLE 6 A pyrotechnic whistling mixture was prepared by weighing 30 grains finely powdered sodium benzoate which was then mixed with 70 grains potassium perchlorate. The mixture was rammed in a tube and a vent drilled as in Example 1. Upon ignition, the device performed in the same manner as in Example 1.

EXAMPLE 7 The procedure in Example 1 was followed except the size of the vent openings was varied and the results obtained are as set forth in Table I, below:

TABLE I Diameter of Vent Openings Results Obtained 1/16 inch Ignited with difficulty, loud buzzing sound resulted 3/32 inch Ignited with difficulty, loud buzzing sound resulted [/8 inch Good ignition, loud buzzing sound (best) 5/32 inch Good ignition, loud buzzing 3/16 inch Buzzing mixed with some hissing /64 inch Reduced buzzing, much hissing V4 inch Predominantly hissing EXAMPLE 8 The procedure K125515151? 7 was followed except the size of the reaction chamber had an inside diameter' of inch and the vent openings were varied and results obtained are set forth in Table II, below.

TABLE 11 Diameter of Vent Openings Results Obtained The procedure i n Exampl7was followedexcept the size of the reaction chamber had an inside diameter of inch and the vent openings were varied and results obtained are set forth in Table III, below:

TABLE III Diameter of Vent Openings Results Obtained 3/32 inch Ignited with difficulty, loud buzzing /6 inch Good ignition, loud buzzing 3/16 inch Good ignition, loud buzzing V4 inch Loud buzzing (best) 5/16 inch Loud buzzing mixed with some hissing it: inch Predominantly hissing, almost a whistle, buzzing suppressed In Examples 7, same, it was found that the ideal size of the vent openings was about one-third of the inside diameter of the reaction chamber. If the openings are much greater than one-half of the inside diameter, the device loses much of the snapping, buzzing sound. If the vent openings are less than 1/16 inch, the device is ignited only with difficulty.

The invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive and the scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope.

What is claimed and desired to be secured by United States letters Patent is:

l. A pyrotechnic device for developing a buzzing sound comprising:

a reaction chamber;

a pyrotechnic whistling mixture confined within the reaction chamber; and

at least one choked opening in the reaction chamber,

said choked opening remaining substantially intact throughout the combustion of the whistling mixture and having a diameter falling within the range of from 1/ 16th of an inch to one-half the inside diameter of the reaction chamber, wherein said l /16t h of an inchi s not greater than oneiia lfitlie inside diameter of the reaction chamber.

2. A pyrotechnic device as defined in claim 1 wherein said reaction chamber is cylindrical in configuration.

3. A pyrotechnic device as defined in claim 1 wherein said pyrotechnic whistling mixture comprises at least one oxidizing agent selected from the group consisting of potassium chlorate and potasssium perchlorate mixed with at least one of the aromatic compounds selected from the group consisting of sodium salicylate, gallic acid, potassium benzoate and sodium benzoate.

4. A pyrotechnic device as defined in claim 1 wherein said reaction chamber comprises at least two choked openings.

5. A method for forming a buzzing pyrotechnic device comprising:

obtaining a reaction chamber;

filling the reaction chamber with a pyrotechnic whistling mixture; and

venting the reaction chamber at at least one location,

said venting step comprising forming an aperture in the reaction chamber, which aperture remains substantially intact throughout the combustion of the whistling mixture and has a diameter falling within the range of from 1/ 16th of an inch to one-half the inside diameter of the reaction chamber, wherein said 1/ 16th of an inch is not greater than one-half the inside diameter of the reaction chamber. 

1. A pyrotechnic device for developing a buzzing sound comprising: a reaction chamber; a pyrotechnic whistling mixture confined within the reaction chamber; and at least one choked opening in the reaction chamber, said choked opening remaining substantially intact throughout the combustion of the whistling mixture and having a diameter falling within the range of from 1/16th of an inch to one-half the inside diameter of the reaction chamber, wherein said 1/16th of an inch is not greater than one-half the inside diameter of the reaction chamber.
 2. A pyrotechnic device as defined in claim 1 wherein said reaction chamber is cylindrical in configuration.
 3. A pyrotechnic device as defined in claim 1 wherein said pyrotechnic whistling mixture comprises at least one oxidizing agent selected from the group consisting of potassium chlorate and potasssium perchlorate mixed with at least one of the aromatic compounds selected from the group consisting of sodium salicylate, gallic acid, potassium benzoate and sodium benzoate.
 4. A pyrotechnic device as defined in claim 1 wherein said reaction chamber comprises at least two choked openings.
 5. A method for forming a buzzing pyrotechnic device comprising: obtaining a reaction chamber; filling the reaction chamber with a pyrotechnic whistling mixture; and venting the reaction chamber at at least one location, said venting step comprising forming an aperture in the reaction chamber, which aperture remains substantially intact throughout the combustion of the whistling mixture and has a diameter falling within the range of from 1/16th of an inch to one-half the inside diameter of the reaction chamber, wherein said 1/16th of an inch is not greater than one-half the inside diameter of the reaction chamber. 